*Control-d does not exit the shell; only "quit" does.
*Haskell expression seem to get evaluated, but their result is not shown!
*Control constructs like && and & or || do not seem to work.
*Every successful commands exits with 'user error (1)'.
*The GHC API requires an absolute path to the GHC lib/ directory. This is currently hardcoded in Eval.hs, but should be in the configuration file.